1. Field of the Invention
The invention generally relates to film advancing means in photographic cameras, and more particularly to apparatus for threading a film leader from a film cassette onto a take-up core in the camera.
2. Description of the Prior Art
Cameras provided with film threading apparatus are well known to those familiar with the photographic art. For example, U.S. Pat. No. 3,463,071, issued to Winkler on Aug. 26, 1969, discloses one type of film threading apparatus for a 35 mm still camera. In the camera, the threading apparatus consists of a guide member for directing a film leader, extending from a film cassette, toward a take-up core and a plurality of leaf springs for securing the leader to the take-up core. A conventional metering sprocket is used to drive the film leader past the guide member toward the take-up core and to prevent lateral misalignment of the leader with the leaf springs. While this structure is generally reliable, the need to position the film leader on the metering sprocket requires operator involvement and prevents threading from being fully automatic.